What is Serverless Computing?
Serverless Computing Defined
Serverless computing is a cloud architecture that allows organizations to get on-demand access to the resources they need. Customers only pay for the resources they use. Resources are not allocated to an application when it is not in use.
In a serverless computing architecture, a server’s code execution is fully managed by the cloud provider. Therefore, the provider’s customers do not need to develop and deploy the underlying infrastructure that would traditionally be required to run applications and programs. The primary objective of serverless computing is to make it easier for software developers to create code that is intended to run on cloud platforms and perform a clearly defined role.
The term "serverless" can be misleading because servers are still required to provide services and resources to organizations. However, these servers are hosted and managed by vendors, enabling developers to go about their coding work rather than worry about handling servers.
How Serverless Computing Came About
To build a web application in the early days of the internet, a developer had to own the hardware they required to run a server. This was an expensive and difficult-to-manage process that was soon remedied by cloud computing, which enabled users to rent a fixed number of servers or a certain amount of server space.
However, developers who rented server space through cloud computing would typically end up over purchasing to allow for spikes in traffic and activity that would affect application performance. This inevitably led to server space going to waste, which further drained organizations’ resources.
Serverless computing enables developers to only purchase the backend services they need, when they need them. It offers a pay-as-you-go solution that people are increasingly accustomed to using in their personal lives and in a business environment.
Advantages of Serverless Computing
Serverless computing offers several key benefits for organizations. These include:
- Lower costs: Serverless computing is a highly cost-effective process that removes the need for expensive underlying cloud architecture and hardware. Customers only pay for the resources they need when they need them, which ensures they do not get lumbered with expensive license fees for services they no longer require or use.
- Simplified scalability: Developers that use a serverless architecture no longer have to concern themselves with policies that define how they scale up their code. The cloud provider’s serverless architecture handles all aspects of scaling on-demand.
- Simplified backend code: Serverless computing enables developers to use simplified backend code that performs a single purpose, such as making a call to application programming interfaces (APIs).
- Improved time to production: Using serverless architecture can help developers significantly reduce the amount of time it takes to bring applications to market. Traditional application development featured complicated processes that allowed for time to fix bugs and ensure new features were secure. But a serverless development model reduces the number of steps it takes to conceive, deploy, and test code, which enables developers to quickly add and modify their code in real time. As a result, the time it takes for an application to go from idea to production can be reduced from months to days.
- Increased productivity: Serverless computing enables developers to be more productive by removing the need to focus on time-consuming issues like bootstrapping, housekeeping, and environmental matters. They are therefore free to focus on developing code and scaling applications.
- Improved security: Serverless computing constrains developers to only using code that works within a serverless context. This means developers are more likely to create code that meets their organization’s best practices and security and governance protocols.
Serverless Computing Elements
Serverless computing is formed of various elements of virtual resources, including:
- Serverless stacks: Serverless computing has led to an evolution toward serverless stacks, which combine the various components organizations need to build their serverless applications. Each stack contains the programming language used to write the code, the application framework that offers the structure for their code, and triggers that the platform uses to understand and initiate code execution.
- Serverless frameworks: The framework that developers use to structure their code defines how they build an application. There are various options available including cross-platform models and open-source frameworks. These include the open-source Serverless Application Model (SAM) by Amazon Web Services (AWS), Apex, and Serverless.
- Serverless databases: Serverless computing means that code does not have a persistent state that needs to be stored somewhere. Major vendors offer serverless databases that interact with developers’ functions and take the backups, maintenance, replication, and scaling away from them.
- Containers: Containers managed by vendors, such as orchestration platform Kubernetes, are responsible for powering serverless technology. However, serverless computing can also be used to reap the benefits of containerized microservices without the complexity of managing them.
- Serverless offline testing: Getting started with serverless computing can appear intimidating and a big commitment at first look. However, features such as AWS’ SAM and serverless-offline offer local features that enable developers to test their code offline on their own local hardware.

How Does Serverless Compare to Other Cloud Backend Models?
Serverless computing is distinct from other forms of cloud backend models and services that organizations can use to build and manage their applications. Other popular cloud backend models include:
Backend-as-a-Service (BaaS)
A BaaS model involves organizations outsourcing all the backend services of their mobile or web application to a BaaS vendor. The vendor provides software for activity that takes place on the organization’s servers, including database management, cloud storage and hosting, remote updating, pushing notifications, and user authentication.
As a result, a BaaS approach allows developers to focus on writing and maintaining their front-end code.
Platform-as-a-Service (PaaS)
A PaaS model involves an organization renting the resources they need to develop and deploy mobile and web applications from a cloud provider. This typically includes renting tools like middleware and operating systems from the web as opposed to storing them on local machines and computing environments. The platform is stored in the cloud and delivered through the internet, which frees up developer teams to focus on infrastructure, software updates, and storage.
PaaS applications are not as scalable as those developed through serverless computing, can have noticeable startup delays, and do not always run on the edge.
Infrastructure-as-a-Service (IaaS)
An IaaS model involves a vendor hosting an organization’s entire cloud infrastructure. This includes virtual computers, hard drives, routers, and servers that store data and run code, as well as the appliances and wiring that connects this data together. Customers access their cloud infrastructure via the internet, which enables them to build and host applications, run business logic, store data, and anything else they would typically be able to on their traditional on-premises infrastructure.
Risks of Serverless Computing
Serverless architecture can be difficult for organizations to secure because of its distributed nature. This makes the architecture more flexible and scalable, which renders traditional security solutions ineffective. Instead, organizations need to focus on securing the functions of applications, which are event-driven and loosely coupled, rather than securing the applications themselves.
Serverless computing also presents visibility issues as developers take the lead, which can result in applications being pushed to production before being addressed by security teams. This can leave the application vulnerable to code-based threats like cross-site scripting (XSS), remote command execution, and Structured Query Language (SQL) injection.
Data storage and transportation also present a security and compliance risk in serverless computing. Data held in stateless and serverless functions remains cached rather than stored in memory, which runs the risk of leakage when moved to external locations.
What Is Next for Serverless Computing?
The serverless architecture market is growing rapidly, with estimates projecting an expansion of more than 20% CAGR over the next five years. In a recent survey, 59% said serverless computing improved either app development or productivity. But what are the factors driving the growth of the serverless computing industry?
What Is Serverless Security?
A cloud computing operational approach is typically referred to as "serverless," and serverless security involves building additional protection layers around modern applications built on serverless and other cloud-based platforms.
What Are the Top 3 Serverless Security Threats?
The top three serverless security threats include:
- Over-privileged functions: This is when a function has more permissions than it needs. In this way, it can be abused to attack key systems or exfiltrate or corrupt data.
- Groundhog day attack: This is when an attacker does not give up after a serverless function reaches its end of life. Instead, they change the nature of the attack or break it up into smaller chunks. For example, they may exfiltrate data in a few short bursts instead of stealing a large amount all at once.
- Poisoning the well: This is when attackers try to incorporate malicious code into widely used projects.
Finding Solutions to Complexities
Within the established serverless computing definition—a cloud computing environment that automatically provisions and scales resources—some complications have to be dealt with. However, the technology is evolving as providers work to come up with solutions.
For example, in its early stages, a well-known disadvantage of serverless computing was “cold starts.” A cold start is when a user or system does not call up a serverless function for a period of time and the provider shuts it down to save resources, basically making the function dormant. But this also means that when the function is next called up, the provider has to spin it up again, and this can result in latency.
Providers have addressed this problem by preemptively spinning up serverless functions in advance. An example is some platforms spinning up the serverless function during the TLS handshake. Since it takes less time to initiate than the handshake, this means that it’s already spinning when called upon, resulting in zero latency.
Benefits for DevOps
Serverless computing provides tangible benefits for DevOps teams, especially those who operate in the cloud:
- Ease of management. DevOps teams working in the cloud may be managing modular components via a pipeline. Transitioning to serverless computing via AWS—and other solutions—can reduce or even eliminate pipeline management, allowing the team to narrow their focus to development and deployment.
- Automation. Serverless computing also makes automation of infrastructure tasks simple, improving productivity and flexibility.
- Outsourcing. Teams using serverless computing can also outsource information, freeing up the team to focus on front-end development.
Advancements in Cloud Computing
According to the standard serverless computing meaning, applications are hosted in the public cloud. Therefore, rapid advancements in cloud computing technologies are creating an environment for serverless computing to thrive. Amazon, Microsoft, Google, IBM, and other major cloud service providers have already taken advantage of this by offering serverless services.
Increase of Microservices, IoT, and BYOD
Organizations are choosing microservices as the preferred technique for designing applications. Since serverless computing follows similar principles in the way it runs applications, the two technologies work hand in hand. In addition, globalization and digital transformation are driving the increased adoption of edge computing, IoT, and BYOD policies. Serverless computing enables organizations to rapidly expand to support these growing needs while reducing setup and management costs.
How Fortinet Can Help
Fortinet helps organizations protect their applications with its FortiWeb web application firewalls (WAFs). FortiWeb protects business-critical applications from known vulnerabilities and zero-day attacks. It uses machine learning to identify anomalous behavior then block and mitigate bots and other malicious activity.
Additionally, FortiWeb evolves as an organization’s attack surface expands, enabling businesses to safely deploy new features, update existing features, and expose new APIs. The solution protects business applications regardless of where they are hosted, meaning they can be used to secure all cloud environments, containers, hardware appliances, cloud-native Software-as-a-Service (SaaS) solutions, and virtual machines.
FAQs
What is serverless computing?
Serverless computing is a cloud architecture that allows organizations to get on-demand access to the resources they need. Customers only pay for the resources they use, and resources are not allocated to an application when it is not in use.
How does serverless computing work?
Serverless computing works through vendors managing servers and server code execution on behalf of their customers. This means organizations do not have to develop or deploy the infrastructure that is required to run applications and programs.
Why is it called serverless?
It is called serverless because organizations do not have to manage their own servers. Instead, vendors are responsible for hosting and managing servers and server code execution. This enables developers to focus on writing their code.